Method of pressure transfer sheet and resulting article



-26,1965 RRWISSINGER ETAL 3 214,285

METHOD OF PRESSURE TRANSFER SHEET AND RESULTING ARTICLE Filed Aug. 10, 1962 By Ga /w H. EHRHARDT WW ,1

ATTOPN vs United States Patent 3,214,285 METHOD OF PRESSURE TRANSFER SHEET AND RESULTING ARTICLE Robert R. Wissinger, Des Moines, and Gerry H. Ehrhardt,

West Des Moines, Iowa, assignors, by mesne assignments, to Pacific Industries Inc., San Francisco, Calif., a corporation of California Filed Aug. 10, 1962, Ser. No. 216,184 6 Claims. (Cl. 11736.4)

Our invention relates to the art of transfer of images by printing, writing pressure, or type impact which act through a transfer sheet having the characteristics of carbon paper.

The image produced by the ordinary carbon paper is satisfactory for most purposes but has a tendency to smear and spread out if handled or used with card feeder and handling equipment which are used with data processing machines. When the image is smeared or spread out, the ability of the machines to accurately scan these images is greatly impaired. Furthermore, because of the poor release characteristics of the coating material from the transfer sheet of ordinary carbon paper, there is also a tendency for the carbon paper not to reproduce an image having an adequate signal level or uniform dimensions for the image to be automatically and accurately scanned. Thus, the new data processing equipment has made it necessary to produce images which are smear-resistant; which have uniform dimensions, and which produce identical signal level for response within such machines.

Therefore, the principal object of our invention is to provide a method and means for producing complete release and smear-resistant images in pressure transfer media which will permit an image to be imparted to a copy sheet wherein the image cannot be smeared from normal use requirements.

A further object of our invention is to provide a method and means for producing complete release and smearresistant images in pressure transfer media which will permit an image to be imparted to a copy sheet wherein the images Will be of constant dimension and Will provide an adequate signal level to insure correct reading thereof by automatic sensing equipment.

A still further object of our invention is to provide a method and means for producing complete release and smear-resistant images in pressure transfer media which creates an extremely clean transfer sheet with a transfer layer that has nearly complete release from the sheet so as to be adapted for use with high speed data processing output printers.

A still further object of our invention is to provide a method and means for producing complete release and smear-resistant images in pressure transfer media which creates images of good legibility and sharpness.

A still further object of our invention is to provide a method and means for producing complete release and smear-resistant images in pressure transfer media which can create an image readily adapted for heat transfer, transfer posting, hectograph paper and similar products.

A still further object of our invention is to provide transfer sheets having a coating of two distinct layers of strata which may be transferred simultaneously from the transfer sheet onto the copy sheet.

These and other objects will be apparent to those skilled in the art.

Our invention consists in the construction, arrangements, and combination of the various parts of the device, whereby the objects contemplated are attained as hereinafter more fully set forth, specifically pointed out in our claims, and illustrated in the accompanying drawings, in which:

FIGURE 1 is a partial perspective view of our pressure sensitive transfer sheet magnified to a large proportion and illustrating its component parts. This figure shows the component parts at the time of initial fabrication;

FIGURE 2 is a partial perspective view of our pres sure sensitive transfer sheet after the silicone layer has cured and has dispersed into the ink layer and the transfer sheet;

FIGURE 3 is a partial perspective view of a copy sheet magnified to a large proportion whereon an image has been imparted by the application of pressure to our pressure sensitive transfer sheet;

FIGURE 4 is a schematic sectional view of a copy sheet that has received an image from our pressure sensitive transfer sheet. The two sheets are shown in spaced apart condition to better illustrate their structure and the phenomenon involved.

We have used the numeral 10 to generally designate our pressure sensitive transfer layer. Layer 10 includes a carrier sheet 12 of thin, flexible material which is commonly a desired grade of paper. A coating layer 14 of silicone or a silicone-type material is adjacent to and in engagement with sheet 12, and the detachably thereto by its own adhesive characteristics as will be discussed hereafter. An ink layer 16 is adjacent to and in engagement with the coating layer 14. The layers 14 and 16 are held together by the afiinity that the materials in the respective layers have for each other. This phenomenon will also be described further hereafter.

In FIGURES 3 and 4, we have shown a copy sheet 18, which has an image 20 imparted thereon in the form of the letter r by the exertion of pressure on the top side 22 of carrier sheet. 12. This pressure can be exerted in any desired manner, such as the impact of a typewriter key, or the key of other such equipment. The image 20 is comprised of a coating layer 14A which is of identical material to coating layer 14 on carrier sheet 12. An ink layer 16A identical to the material in ink layer 16 is positioned between and in engagement with both the layer 14A and the copy sheet 18. In FIGURE 4, we have shown images 22 and 24 which have been imparted to copy sheet 18 by the application of pressure to the carrier sheet 12 in the manner described. The images 22 and 24 were releasably detached from the transfer layer 10 as indicated by the exaggerated voids 22A and 24A in the transfer layer. The images 22 and 24 are each comprised of an outer coating layer 14B which is positioned on an ink layer 16B; the layers 14B and 16B being identical to the layers 14 and 16, respectively, on the transfer sheet 10.

The coating layer 14 of silicone or the like serves at least two very important functions. It first of all serves as a release agent for permitting the images 20, 22 and 24 to be released from the carrier sheet 12. Secondly, it provides, as layers 14A and 14B, a protective coating for the ink layers 16A and 16B, respectively, to prevent these ink layers from being easily smeared after the images are imparted to the copy paper. Furthermore, the layers 14A and 14B give the images a uniform definition not usually attained by an ink layer alone, and at the same time, the complete release and uniform definition of the resulting image is given a signal potential not consistently achieved by an ordinary carbon ink layer.

The coating layer 14, as indicated above, is preferably comprised of any of the material commonly known as silicone. These materials are polymeric with the base structure of the chain consisting of a. succession of silicone and oxygen atoms (Si-O-Si-O). To each silicone determined by those skilled in the art.

- It has been applied by roll coating, press coating, knife coating and can be sprayed onto the carrier sheet 12. The

a silicone can be applied from an aqueous solution, solvent solution, or a combination of the two. It also can be applied from nearly any hydrocarbon composition.

The amount of silicone applied is dependent upon the desired results. The amount needed can readily be Silicone in the amount of 0.1 to 0.5 pound per 300,000 square inches of a carrier sheet 12. will produce good results.

Silicone and silicone-type materials give effective release under the most severe conditions. It is also known that silicones are very resistant to smear since the surface of these materials provide little or no friction. A typical formulation for the silicone coating is:

33% of Syl-off 23 (Dow Chemical Co.) 66% Solvent 1% Catalyst 23A (Dow Chemical Co.)

Some of the materials which can be used for the silicone coatings are: Silicone emulsions, silicone OllS, silicone greases, silicone plastics, silicone varnishes, and

. silicone rubber.

The ink layer 16 can be comprised of formulations typical in the carbon paper art. A normal formulation for ink layer 16 is as follows:

- Percent Carnauba wax 40 Parafl'ln wax 20 Mineral oil Carbon black I- 10 layer and ink layer to provide an easily releasable nonsmearing image on a copy sheet have been overcome by our novel method of combining these components.

The silicone or coating layer 14 is applied to the carrier sheet 12 in any of the manners described above and the ink layer 16 is separately applied to the then silicone-coated sheet 12 by conventional means. The silicone is applied either with or without a catalyst. A key feature of this technique is that the ink layer must be applied to the silicone before the silicone has cured. Before the silicone is cured, it will disperse and penetrate the ink layer 14 and the carrier sheet 12 to effect a releasable bond with the carrier sheet and a sufficiently permanent bond to the ink layer. Thus dispersing action of the silicone into the carrier sheet 12 and ink layer 14 is indicated by the irregular lines in FIGURES 2, 3, and 4.

It is readily seen that the principles of this invention can be used Whenever an image has to be used for sensing by photoelectric means, magnetic means, electrical con tact means, or by any other means where data processing equipment requires special requirement. It is also seen that the principles of this invention can be used when a carbon paper is used for reproducing copies for high speed output printers where a large number of readable copies must be produced. These principles are of great importance in producing images which are to be transferred by heat or solvent. These images must contain suflicient color to reproduce more copies with the use of solvents or heat. These images must also be smudge resistant and of uniform dimensions. Our method and means will provide such images.

From the above description, it is seen that a novel, coated, pressure sensitive media of the carbon paper type can be produced consisting of two layers which are transferred simultaneously to form a smear resistant image of uniform dimension. The above is accomplished by the use of silicones or silicones products to which a carbon paper ink is applied before the silicone has had sufiicient time to cure, thereby causing the silicone to transfer both to the carbon paper ink and the paper. Thus is produced a good release transfer sheet, and the image resulting will be smear resistant and of uniform dimension. Our invention is therefore seen to accomplish at least all of its stated objectives.

Some changes have been made in the construction and arrangment of our method and means for producing complete release and smear-resistant images in pressure transfer media Without departing from the real spirit and purpose of our invention, and it is our invention to cover by our claims, any modified forms of structure or use of mechanical equivalents which may be reasonably included within their scope.

We claim:

1. The method of producing a pressure responsive transfer media for effecting, responsive to pressure applied thereto, complete release therefrom and transfer to a copy surface of a smear-resistant image, comprising the step of applying to a thin flexible carrier sheet a coating layer consisting essentially of a polymeric silicone in incompletely cured condition, such that said coating layer is partially dispersed in said carrier sheet, the step of applying to the exposed surface of said uncured coating layer an ink layer consisting essentially of carbon paper ink such that said uncured coating layer is partially dispersed in said ink layer, and the step of curing said poly meric silicone coating layer to effect a frangible composite layer on said carrier in which the affinity of said ink layer to said silicone coating layer is greater than the affinity of said silicone layer to said carrier sheet.

2. The method as set forth in claim 1 and in which said curing is accomplished by providing a curing time suitable to the polymeric silicone employed.

3. The method as set forth in claim 1 and in which said curing is accomplished by applying heat to said silicone layer.

4. The method as set forth in claim 1 and in which a catalyst is employed to effect curing of said polymeric silicone layer.

5. The product produced by the method set forth in claim 1.

6. The method of producing a pressure responsive transfer media for effecting, responsive to pressure applied thereto, complete release therefrom and transfer to a copy surface of a smear-resistant image, comprising the step of applying to a thin flexible carrier sheet a coating layer consisting essentially of a polymeric silicone in incompletely cured condition such that said coating layer is partially dispersed in said carrier sheet, the step of applying to the exposed surface of said uncured coating layer an image forming layer including a material sensitive to magnetic sensing means such that said uncured coating layer is partially dispersed in said image forming layer, and the step of curing said polymeric silicone coating layer to effect a frangible composite layer on said carrier in which the affinity of said image forming layer to said silicone coating layer is greater than the afiinity of said silicone layer to said carrier sheet.

References Cited by the Examiner UNITED STATES PATENTS 2,912,344 11/59 Newman et al 117-36.4 3,034,918 5/62 Cook et al. 1l736.4 3,087,832 4/63 Fogle 117-36.4

WILLIAM D. MARTIN, Primary Examiner. MURRAY KATZ, Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No, 3,214,285 October 26, 1965 Robert R. Wissinger et al.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 2, line 26, for "the detachably" read is detachably secured line 68, for "material" read materials same column 2, line 69, for "base" read basic column 3, line 58, for "Thus" read This column 4, line 18, for "invention", second occurrence, read intention Signed and sealed this 14th day of June 1966,

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Atteeting Officer Commissioner of Patents 

1. THE METHOD OF PRODUCING A PRESSURE RESPONSIVE TRANSFER MEDIA FOR EFFECTING, RESPONSIVE TO PRESSURE APPLIED THERETO, COMPLETE RELEASE TEHREFROM AND TRANSFER TO A COPY SURFACE OF A SMEAR-RESISTANT IMAGE, COMPRISING THE STEP OF APPLYING TO A THIN FLEXIBLE CARRIER SHEET A COATING LAYER CONSISTING ESSENTIALLY OF A POLYMERIC SILICONE IN INCOMPLETELY CURED CONDITION, SUCH THAT SAID COATING LAYER IS PARTIALLY DISPESED IN SAID CARRIER SHEET, THE STEP OF APPLYING TO THE EXPOSED SURFACE OF SAID UNCURED COATING LAYER AN INK LAYER CONSISTING ESSENTIALLY OF CARBON PAPER INK SUCH THAT SAID UNCURED COATING LAYER IS PARTIALLY DISPERSED IN SAID INK LAYER, AND THE STEP OF CURING SAID POLYMERIC SILICONE COATING LAYER TO EFFECT A FRANGIBLE COMPOSITE LAYER ON SAID CARRIER IN WHICH THE AFFINITY OF SAID INK LAYER TO SAID SILICONE COATING LAYER IS GREATER THAN THE AFFINITY OF SAID SILICONE LAYER TO SAID CARRIER SHEET. 